JPH0238866B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the operation control of an air conditioner, and is particularly aimed at reducing refrigerant noise generated when switching a solenoid valve that connects high and low pressures of refrigerant.

Conventionally, switching of a solenoid valve was performed simultaneously with the operation of a changeover switch or the generation of a changeover signal. As a result, the high-pressure side and the low-pressure side in the refrigerant piping are instantaneously communicated, producing a loud refrigerant sound as the refrigerant flows, which causes discomfort.

For this reason, attempts have been made to delay the switching of the solenoid valve for a predetermined period of time and switch the switch after obtaining a certain refrigerant pressure balance, but if the delay time is too long, the refrigerant noise may be reduced to some extent, but the air conditioner If there is a significant delay in operation and proper air conditioning cannot be achieved, or if the delay time is too short, refrigerant noise will not be reduced much, and in any of the above cases, refrigerant noise is unavoidable and unpleasant. It was hot.

The present invention has been made in view of such drawbacks, and is an air conditioner including a compressor, a condenser, an evaporator, and a solenoid valve that connects high and low pressures of refrigerant. A delay mechanism that maintains the time, a temporary stop mechanism that temporarily generates a stop signal to the compressor to operate the delay mechanism when the solenoid valve switching signal is generated, and a temporary stop mechanism that operates the delay mechanism by temporarily generating a stop signal to the compressor when the solenoid valve switching signal is generated; By switching the solenoid valve at the same time as the compressor is operating, after a certain refrigerant pressure balance is achieved, the refrigerant noise is made less noticeable by the compressor startup sound, thereby significantly reducing discomfort.

An embodiment of the present invention will be described below based on the drawings. 1 is a constant voltage circuit unit that stabilizes the voltage rectified by a rectifying element 2, and 3 is a negative characteristic thermistor 4 that senses the temperature of the air conditioning room. A comparator 8 is connected to the output terminal of a bridge circuit 6 whose two sides are a variable resistor 5 for changing a temperature value, and generates an operating signal for the compressor by a thermocycle together with a feedback resistor 7. The comparator 12 inputs the signal through the resistor 9 and operates the compressor driving relay 10 and the current-carrying transistor 11, and the resistor 13 and diodes 14 and 15 charge the signal immediately, and when the operation signal stops, the charge is transferred through the resistor 16. A delay mechanism consists of a discharging capacitor 17 to prevent the compressor from starting and stopping for a short period of time, and 18 is a single-pole, double-headed contact type "cooling-dehumidification" changeover switch (during cooling operation, the solenoid valve is set to close, and dehumidification operation is performed). 19 is a resistor 20, 21 whose output is at ground level when the changeover switch 18 is in the non-switching state, and at high potential at other times.
22, 23, a stop mechanism consisting of a diode 24, and a comparator 25; 26 a switching mechanism for a solenoid valve;
The operating signal of the compressor is inputted through a diode 27 to a connection point between resistors 28 and 29, and the other end of the resistor 29 is inputted to an inverting input terminal of a comparator 30, and is connected to the ground level through a resistor 31. . In addition, a series circuit of resistors 32, 33, and 34 is connected between the constant voltage circuit 1 and the earth level.
The non-inverting input terminal of the comparator 30 is connected to the connection point of the resistors 32 and 33, and the connection point of the resistors 32 and 33 is connected to the diode 35,
Changeover switch 18 via light emitting diode 36
The diode 35, 3 is connected to the dehumidifying side of the
7. Connected to the rectifying element 2 via a resistor 38. Further, the light emitting diode 39 has one end connected to the resistor 38 and the other end connected to the cooling side of the changeover switch 18. 40 is a feedback resistor provided in the comparator 30, and 41 is a transistor for controlling energization of the drive relay 42 which switches the electromagnetic valve according to the output of the comparator 30.

Since one embodiment of the present invention is constructed as described above, when the changeover switch 18 is fixed to the cooling side, the comparator 3 connected to the output end of the bridge circuit 6 adjusts the compression according to the thermocycle. A machine operation signal is generated. When the charge of the capacitor 17 in the delay mechanism 8 is discharged, the low potential generated by the resistors 21 and 23 is applied to the inverting input terminal of the comparator 12, so that the non-inverting input terminal of the comparator 12 is operated at a high potential. When a signal is input, the output of the comparator 12 becomes high potential. Thereafter, the capacitor 17 is quickly charged via the diode 15, the diode 14, and the resistor 13, so that the high potential operation signal from the comparator 12 stops, and at the same time the potential generated by the resistors 21 and 23 and the capacitor are charged. A potential sum of the potential generated by the discharge of the capacitor 17 is applied to the inverting input terminal of the comparator 12, and the potential is maintained at a high potential until the discharge of the capacitor 17 is completed. At this time, since the high potential applied to the inverting input terminal is higher than the high potential operation signal applied to the non-inverting input terminal of the comparator 12 via the resistor 9, the comparator 12 continues until the discharge of the capacitor 17 is completed. The output of remains at a low potential. Further, when the output of the comparator 12 becomes a high potential, the transistor 11 is turned on, the compressor drive relay 10 is energized, and the compressor starts operating. At this time, the light emitting diode 39 is turned on via the changeover switch 18, and the resistor 3
Since the high potential generated by 2, 33, and 34 is applied to the non-inverting input terminal of the comparator 30, the output becomes a high potential, turning on the transistor 41, energizing the solenoid valve drive relay 42, and turning on the solenoid valve. close. At the same time, the potential of the output of the comparator 30 fed back to the non-inverting input terminal by the resistor 40 is higher than the potential applied to the inverting input terminal regardless of whether an operating signal is generated, so that the output is maintained at a high potential. Therefore, the solenoid valve is closed and cooling operation can be performed using the thermocycle.

Next, when the changeover switch 18 is changed over to perform dehumidification operation, the comparator 25 of the stop mechanism 19 is
operates and the output becomes ground level, interrupting the operation signal from the comparator 3, so that the delay mechanism 8 starts operating and the operation of the compressor is stopped for a predetermined period of time to balance the pressure of the refrigerant. When the changeover switch 18 is set to the dehumidifying side, the light emitting diode 36 lights up, and at the same time, the voltage between the light emitting diode 36 and the diode 37 is maintained at about 0.6 to 0.7 [V] due to the Zener effect of the light emitting diode 36, and the resistor 32,
The potential generated between 33 and 33 becomes a low potential. However, due to the feedback of the resistor 40, the non-inverting input terminal of the comparator 30 is maintained at a high potential, and the output of the comparator 30 is maintained at a high potential.

Thereafter, when the discharge of the capacitor 17 of the delay mechanism 8 is completed and a thermocycle operation signal is generated from the comparator 3, a high potential is applied between the resistors 28 and 29 via the delay mechanism 8 and the diode 27. As a result, a high potential generated by the resistors 29 and 31, which is higher than the potential applied to the non-inverting input terminal, is applied to the inverting input terminal of the comparator 30, and the output of the comparator 30 becomes the ground level. After this, the non-inverting input terminal is maintained at a low potential due to the Zener effect of the light emitting diode 36, so the output of the comparator 30 becomes the ground level regardless of the generation of the operation signal, the transistor 41 remains OFF, and the solenoid valve opens. The state will be as follows. Therefore, when the compressor is started after the pressure of the refrigerant is balanced, the solenoid valve is switched and the refrigerant noise can be reduced.

It should be noted that the delay mechanism, stop mechanism, and electromagnetic valve switching mechanism in the present invention are not limited to the above configurations, but may also be configured using software such as a computer. For example, when configured using a microprocessor, the delay mechanism includes a timer that starts decrementing from a predetermined value when there is a compressor stop signal, and a timer that starts decrementing from a predetermined value when the compressor stop signal is received. It consists of a logic part that drives the compressor when there is a machine operation signal, and the stop mechanism uses the switching signal of the solenoid valve (close → open, open →
The solenoid valve switching mechanism actually switches the solenoid valve based on the logical product of the compressor operation signal output from the delay mechanism and the stop signal. It is only necessary to configure the software and hardware so that the operation can be performed.

The air conditioner control device of the present invention includes a compressor, a condenser, and a solenoid valve that connects high and low pressures of refrigerant. A temporary stop mechanism that generates a stop signal to the compressor when a switching signal is generated, and a solenoid valve switching mechanism that switches the solenoid valve when restarting the compressor after generation of the solenoid valve switching signal. Therefore, the refrigerant noise can be reduced by delaying the switching of the solenoid valve for at least a predetermined period of time to balance the pressure of the refrigerant, and then switching the solenoid valve. Further, it is possible to use both the delay mechanism for protecting the compressor and the delay mechanism for the electromagnetic valve, thereby reducing the cost and simplifying the circuit. Furthermore, the electromagnetic valve is switched when the compressor is started, and the refrigerant temperature at the electromagnetic valve becomes inconspicuous due to the start-up sound of the compressor, which eliminates the discomfort caused by the refrigerant noise, which is extremely effective.

[Brief explanation of drawings]

The drawing is an electrical circuit diagram showing an embodiment of the device of the present invention. 8...Delay mechanism, 19...Stop mechanism, 26...
Solenoid valve switching mechanism.

Claims (1)

[Claims] 1. A control device for an air conditioner that is equipped with a solenoid valve that connects high and low pressures in a refrigeration cycle that includes a compressor, a condenser, a pressure reducer, and an evaporator, and that controls the operation of the compressor based on room temperature, A signal output mechanism that outputs a compressor operation signal or a compressor stop signal based on room temperature, and a signal output mechanism that starts measuring a predetermined time in response to the compressor stop signal and stops the compressor while the predetermined time is being measured. a delay mechanism that maintains the state, a changeover switch that sets the open/closed state of the solenoid valve, a stop mechanism that outputs a compressor stop signal to the delay mechanism based on the operation signal output when changing the setting of this changeover switch, When there is a compressor operation signal after the mechanism finishes timing the specified time and the changeover switch is set to the open state, the solenoid valve is opened.
Also, after the time measurement ends, there is a compressor operation signal,
A control device for an air conditioner, further comprising an electromagnetic switching mechanism that closes the electromagnetic valve when the switching switch is set to the closed state.